Niue (population 1,751 (1992)) is a self governing territory in free association with New Zealand (similar to the
Cook Islands I wrote about earlier). Niue is fully responsible for its internal affairs; New Zealand retains responsibility for foreign affairs. Niue achieved this status in 1974. Its "yellow ensign" flag was adopted in 1975. Stuart Park, 15
December 1995

Crampton's "World of Flags" states that the yellow field is to symbolize "the warm friendship between Niue and New Zealand", whose colony Niue is.

Reading between the lines some, I gather this flag was something of a tribute to New Zealand: they wanted something yellow for the friendship angle, and they wanted to honor their host country by making the flags similar...so they made it a yellow field and moved the five stars usually found on the NZ flag to the canton.

Taken this way, I'm not even sure that the islanders even considered Britain at all in "defacing" the Union Flag. To them, it was part of NZ's flag, just a pretty, striped canton, and they innocently modified it for their own friendly purposes.

With any luck, the British won't be floating battleships into Alofi (Niue's capital) and demanding of the confused islanders that they remove those stars...
:-) Steve `Scooter' Kramer, 9 June 1996

The Niue Consulate in Auckland (New Zealand) has provided some official details about the Niue flag. It reads:

The Niue National Flag shall be described as follows :

"The Niue National Flag shall be a golden yellow Flag, bearing in the upper canton of the hoist thereof the Union Flag, commonly known as the Union Jack, displaying two five-pointed yellow stars on the vertical line and on the horizontal line thereof separated by a blue disc containing a larger yellow star."

And it shall mean:

"Golden yellow" represents the bright sunshine of Niue and the warm feelings of the Niuean people towards New Zealand and her people.
"The Union Flag, commonly known as the Union Jack" represents that Niue was a British Protectorate, proclaimed on 19 October 1900 after petitioning by the Kings and Chiefs of Niue to Great Britain for the Union Flag to be flown in Niue as the symbol of protection.
"The four small stars" represent the Southern Cross and New Zealand under whose administration Niue was placed by Great Britain in 1901 and as well the continuing close relationship between Niue and New Zealand.
"The larger star within the blue disc" represents the self-governing status of Niue, standing alone within the deep blue sea.

Stuart Park, 28 June 1996

I assume that the height (not circle's diameter) of the stars on the horizontal crossbar and the width of the stars on the vertical crossbar are identical to the St. George cross' thickness, and that the central star and circle have a diameter identical to the St. George cross' thickness, including fimbriations.
António Martins 2 February 2000

If this is so, wouldn't that make the two pairs of stars differently sized on the bars of the St. George's cross? I think that at least as reasonable an assuption as the first one would be that the fours stars are equal. Maybe the fours stars are somewhat less then SGC width? Would half the central star diameter fit? It is hard to tell from any small sited image available to me.
Željko Heimer, 5 February, 2000

A Niuean source provides us with legislation regarding the Niue flag. It was
adopted by the Niue Flag Act 1975, 1975/16 – 1975 (unlike other acts, not more
precise date provided here then simply 1975). It does not provide any
drawings, nor dimensions of the flag and its part, but it provides explanation
of the symbolic. It is short enough to be quoted in extenso (Niue
Laws | Tau Fakatufono-tohi a Niue, Legislation as at December 2006, Volume 3 |
Tohi 3,Statutes, N-Z, Government of Niue, Alofi, 2006, pp. 1365-1366,
http://www.gov.nu/wb/media/Volume%203.pdf):

Niue Flag Act 1975
1975/16 – 1975

To provide for the establishment and use of a Niue Flag
1 Short titleThis is the Niue Flag Act 1975.

2 Niue Flag(1) The
Niue Flag shall be the flag described in the Schedule.(2) The Niue Flag is
hereby declared to be the recognised flag of Niue.(3) Any other flag
hitherto prescribed or used as the recognised flag of Niue is hereby declared
to be disestablished in Niue.

3 RegulationsCabinet may make
regulations prescribing the circumstances in which and the conditions subject
to which the Niue Flag may be flown.

4 OffencesEvery person who
defaces the Niue Flag by placing any sign, representation, or letter thereon
commits an offence, and is liable to a fine not exceeding 5 penalty units or a
term of imprisonment not exceeding 6 months.

ScheduleTHE NIUE FLAG
The Niue Flag shall be described as follows:“The Niue National Flag shall
be a golden yellow flag, bearing on the upper canton of the hoist thereof the
Union Flag, commonly known as the Union Jack, displaying 2 five-pointed yellow
stars on the vertical line and on the horizontal line thereof separated by a
blue disc containing a larger five-pointed yellow star.” AND IT SHALL
MEAN:Golden yellow represents the bright sunshine of Niue and the warm
feelings of the Niuean people towards New Zealand and her people. The Union
Flag, commonly known as the Union Jack represents that Niue was a British
Protectorate, proclaimed on 19 October 1900 after petitioning by the Kings and
Chiefs of Niue to Great Britain for the Union Flag to be flown in Niue as the
symbol of protection. The four small stars represent the Southern Cross and
New Zealand under whose administration Niue was placed by Great Britain in
1901 and as well reflecting the continuing close relationship between Niue and
New Zealand. The larger star within the blue disc represents the
self-governing status of Niue, standing alone within the deep blue sea.

BTW, on the page 1586 in the text of another act (Territorial Sea and
Exclusive Economic Zone Act 1996) it is mentioned "... by vessels carrying the
flag of Niue..." which would imply that the flag of Niue is indeed used not
only on land but also by the vessels registered in Niue, therefore it is
indeed a yellow ensign (and not CS-/--- as "conservatively" indicated on
Wikipedia
http://en.wikipedia.org/wiki/Flag_of_Niue and World Flag Database,
http://www.flags.net/NIUE.htm).Željko Heimer, 21 January 2012

Description of a
flag: "The central big star represents Niue as stand alone nation in
the wide Pacific ocean. The five stars represent the Southern Cross on the Niue
flag which signifies its link to the Commonwealth. The torch and dove go hand in
hand and both represent Mutalau as being the first village of Niue to receive
the gospel. Navy blue is the official Mutalau colour."

The Niue Yacht Club in the South Pacific has a yellow background, with a green
map of Niue Island. The longitude and latitude are given in green: 19 degrees S,
169 degrees 55 W.
Source: The Complete Guide To Clubs & Flags, p. 30Mason Kaye, 11 June 2004